Liquid Storage Means For Supplying Plants

ABSTRACT

A liquid storage means for the supply of plants, whose porous storage material is a hydrophilic foam, in particular formed from urea resin and a tenside, and having open pores.

The invention concerns a liquid storage means for supplying plants,which has a porous storage material.

It is known for example from DE 198 07 379 A1 to use clay granules(expanding clay) for liquid storage purposes when supplying and takingcare of plants, in particular potted plants.

The object of the invention is to provide a liquid storage means whichcan also be used for supply over a large area.

According to the invention that object is attained by the characterisingfeatures of claim 1. The porous, biocompatible storage material isformed by a hydrophilic foam with open pores, wherein the foam ascomponents contains at least one hardened urea component as a supportsubstance and at least one surface-active substance, in particular atenside. The hardenable foam component used is in particular urea resinor melamine resin or another biocompatible foam plastic as the supportsubstance.

The density of the two-component foam is preferably from 15 kg/m³ to 60kg/m³. The foam can be in the form of a moulded foam body or preferablyin the form of flakes. The foam can serve for the storage of a nutrientsolution, in particular an aqueous nutrient solution, water or also anaqueous fertiliser solution.

The foam can be incorporated in the form of a layer in the ground or inthe soil of the plant and substantially accommodate the roots of theplant to be supplied. The foam can be introduced directly into theground on site, with a mobile insertion vehicle. In that case the foamis preferably introduced into the ground, in the form of a closed layer.The layer can be formed by the foam flakes or by one or more mouldedfoam bodies in plate or leaf form. It is also possible for the foam tobe mixed in the form of flakes with the ground which surrounds the rootsof the respective plant to be supplied, or for the foam to be arrangedin a distributed manner in that ground. The foam support may contain afurther solid substance comprising a porous, biocompatible material, forexample expanding clay, volcanic rock or the like. When solid materialis added the density of the foam can be increased to 150 kg/m³.

The foam material acquires hydrophilic properties due to the tensidecomponent and due to the open pores in the foam. In that way it canstore liquid and gradually discharge it to its surroundings, for examplethe ground surrounding the root structure or directly to the roots ofthe plant.

Urea resins (urea-formaldehyde resins) are of the following structuralformula:

wherein R¹ and R² can be hydrogen atoms or identical or differentorganic residues. Suitable urea resins are available on the market forexample for insulating purposes.

Suitable melamine resins are melamine-urea-formaldehyde resins ormelamine-phenol-formaldehyde resins.

The tensides used can be alkyl benzene sulphonate, fatty alcohol ethersulphate, fatty alcohol sulphate or alkyl phenol ethoxylate.Catalytically active acid hardener solutions with a tenside proportionare available on the market. Suitable acids for the hardener solutionare phosphoric acid, citric acid, p-toluene sulphonic acid and otheracids.

An example for the production of the foam substantially comprising twocomponents is described hereinafter.

The urea resin is kept in readiness in a container, in the form of a 50%urea resin dispersion (35% by weight to 50% by weight of resin powderand 65% by weight to 50% by weight of water). Disposed in a furthercontainer is the hardener solution which contains at least one tensideas a surface-active substance. The hardener solution is available on themarket, in concentrated form. The concentration of the hardener solutionused is adjusted in dependence on the composition of the resin/waterdispersion. For foam production, when using a urea resin/waterdispersion with 35% by weight of resin powder and 65% by weight ofwater, one litre of concentrated hardener solution is mixed with 22 l ofwater. When using a urea resin/water dispersion with 50% by weight ofresin powder and 50% by weight of water, one litre of concentratedhardener solution is mixed with 17 l of water. In the foam productionprocedure, the hardener solution is mixed with compressed air, forexample at 400 to 600 l/min, and that pre-formed foam is mixed with theurea resin dispersion, using compressed air. In the binding or hardeningprocess which takes place in that case, the desired, finished foam isproduced. In the binding or hardening process, the biocompatible solid,for example expanding clay or volcanic rock, can be introduced into thefoam support. It is also possible for a biocompatible colouringmaterial, for example a food dye, to be introduced into the foamsupport. The foam which issues in flake form by way of one or morenozzles is in the form of flakes and can be applied for example over alarge area In the form of a layer or mixed with topsoil. In agriculturethe foam flakes can be for example ploughed under. In the home or in thegarden the foam flakes can be mixed with the plant soil.

It is also possible For the foam issuing from the nozzle or nozzles tobe introduced into a mould for forming a moulded foam body.

The invention will be described in still further detail with referenceto the Figures in which:

FIG. 1 shows a first embodiment by way of example of the invention, and

FIG. 2 shows a second embodiment by way of example of the invention.

The Figures show a plant 6 with associated root 5. In the embodiment ofFIG. 1 the root 5 is disposed substantially in a foam layer 1 which hasopen pores and hydrophilic properties. The foam layer 1 can be formedfrom foam flakes 2. The foam layer 1 can be in the form of a closedlayer of foam flakes or it can be formed by one or more moulded foambodies of a plate shape. The foam layer 1 is still covered with soil 3.The closed foam layer 1 can be introduced directly into the earth onsite with a mobile insertion vehicle.

In the embodiment of FIG. 2 the foam flakes 2 are mixed with the soil 4surrounding the root 5 of the plant 6.

In both embodiments the foam is in the form of a liquid storage meanswhich can store received nutrient solution, water or fertiliser solutionover a prolonged period of time and deliver it in a metered manner tothe root 5 of the plant 6. As micro-organisms and naturally occurringbacteria are not washed out in the case of the foam according to theinvention, natural humus formation is promoted. Salting of the ground isminimised. The foam formed from the urea resin and the tenside isbiodegradable, whereby it is possible to achieve additional plantfertilisation, as has been found in the case of long-term tests. Testswhich have been carried out showed that, with 20% by volume of foamflakes mixed with the soil, a water saving of about 30% was achieved. Awater saving of approximately 90% is achieved when applying the foam inthe form of a foam layer.

The foam according to the invention is suitable not only for liquidstorage means which are spread over a large area but also as liquidstorage means in the case of plants growing in containers or pots or inthe form of liquid storage means in point form, for supplying anindividual plant.

LIST OF REFERENCES

-   1 foam layer-   2 foam flakes-   3 soil-   4 soil surrounding root-   5 root-   6 plant

1. A liquid storage means for supplying plants, which is formed from aporous storage material, characterised in that the porous storagematerial is formed by a foam with a hardened, biocompatible andopen-pore plastic foam support which contains a surface-activesubstance, in particular at least one tenside, as a component.
 2. Aliquid storage means according to claim 1 characterised in that theplastic foam support is formed by a urea resin or melamine resin
 3. Aliquid storage means according to claim 1 or claim 2 characterised inthat the foam is in the form of a flakes or in the form of a mouldedbody or is introduced directly into the ground in the form of a closedlayer by means of a mobile insertion vehicle.
 4. A liquid storage meansaccording to one of claims 1 to 3 characterised in that the foam is of adensity of from 15 kg/m³ to 60 kg/m³.
 5. A liquid storage meansaccording to one of claims 1 to 3 characterised in that the foam supportalso includes a biocompatible solid material.
 6. A liquid storage meansaccording to one of claims 1 to 5 characterised in that the foam with aproportion of solid material is of a density of up to 150 kg/m³.
 7. Aliquid storage means according to one of claims 1 to 6 characterised inthat the foam support has a colouring agent.
 8. A liquid storage meansaccording to one of claims 1 to 7 characterised in that the foam servesfor the storage of water, aqueous nutrient solution or aqueousfertiliser solution.
 9. A liquid storage means according to one ofclaims 1 to 8 characterised in that it is arranged in the form of a foamlayer in the region of the plant root.
 10. A liquid storage meansaccording to one of claims 1 to 9 characterised in that the foam flakesare mixed with the soil surrounding the plant root.